The present invention relates generally to the field of electrical sensors and more particularly to a network based multi-function sensor and control device suitable for sensing motion, temperature, humidity and ambient light, setting and controlling temperature and control relay and ballast loads and which includes blinder devices for reducing nuisance tripping of the device.
Today, automation systems are being installed in more and more buildings, including both new construction and in structures that are being rebuilt. The incentives for putting automation systems into a building are numerous. High on the list are reduced operating costs, more efficient use of energy, simplified control of building systems, ease of maintenance and of effecting changes to the systems. Facility managers would prefer to install systems that can interoperate amongst each other. Interoperability is defined by different products, devices and systems for different tasks and developed by different manufacturers, being able to be linked together to form flexible, functional control networks.
An example of a typical automation system includes lighting controls, HVAC systems, security systems, fire alarm systems and motor drives all possibly provided by different manufacturers. It is desirable if these separate disparate systems can communicate and operate with each other.
Prior art automation systems generally comprised closed proprietary equipment supplied by a single manufacturer. With this type of proprietary system, the installation, servicing and future modifications of the component devices in the system were restricted to a single manufacturer""s product offering and technical capability. In addition, it was very difficult or impossible to integrate new technology developed by other manufacturers. If technology from other manufactures could be integrated it was usually too costly to consider.
Thus, it is desirable to create an open control system whereby individual sensors, processors and other components share information among one another. A few of the benefits of using an open system include reduced energy costs, increased number of design options for the facility manager, lower design and installation costs since the need for customized hardware and software is greatly reduced and since star configuration point to point wiring is replaced by shared media and lastly, system startup is quicker and simpler.
In addition, expansion and modification of the system in the future is greatly simplified. New products can be introduced without requiring major system redesign or reprogramming.
An integral part of any automation control system are the sensors and transducers used to gather data on one or more physical parameters such as temperature and motion. It would be desirable if a plurality of sensor functions could be placed in a single device, fit in a standard single wall box opening and be able to communicate with one or more control units, i.e., processing nodes, on the control network.
The number and types of sensors in this device could be many including multiple, dual or singular occupancy and security sensing via means including passive infrared, ultrasonic, RF, audio or sound or active infrared. In addition, other multiple or singular transducers may be employed such as temperature sensor, relative humidity sensor, ambient light sensor, CO sensor, smoke sensor, security sensor, air flow sensors, switches, etc.
The utility of such a multifunction sensor can best be described by an example. In order to minimize the number of unique devices that are installed in a room, it is desirable to have a sensor device reliably perform as many functions as possible as this reduces the wiring costs as well as the number of devices required to be installed on the walls of the room. Additionally, from an aesthetic point of view, architects are under increasing demand by their clients to reduce the number of unique sensor nodes in any given room.
Further, it is also desirable to have these transducers or sensors communicate with a microprocessor or microcontroller that can be used to enhance the application of the transducer. This may be accomplished by providing the necessary A/D functions, including sensitivity and range adjustments of the transducer functions, and also by enabling the sensed information to be communicated over a bus or other media using a suitable protocol.
Further, calibration,either in the field or the factory could be employed to generate either a relative or real absolute temperature reading. Further, the control of any HVAC equipment could be performed either locally at the sensor node or at a remote location. Also, the sensor devices could be used to control the lights in and outside the room and building, control the HVAC controls in and outside the room and building, send signals to or control the fire alarm and security alarm systems, etc.
It is also desirable to enable the device to communicate using any of the standard protocols already in use such as Echelon LonWorks, CEBus, X10, BACNet, CAN, etc. Some examples of the media include twisted pair, power line carrier, optical fiber, RF, coaxial, etc.
The device thus preferably can transmit data or commands, receive data or commands, activate and switch local or remote loads or control devices, use and/or generate real time or relative readings, be calibrated externally in an automatic self adjusting way, calibrated externally or via an electronic communications link. The ability to communicate over a network allows the user or network manager the flexibility to set light levels, temperature and humidity levels in the building to desired levels either for maximizing the energy savings or for the occupants comfort or convenience or for some combination of the two.
Additionally, the device preferably is able to minimize or eliminate effects from its internal circuitry that may interfere with the temperature reading of the temperature sensor. Also, the device preferably has the ability to detect if there are adverse air flows emanating from the mounting hole in the wall or other surface which could cause erroneous temperature and humidity measurements.
It is desirable if the device is mounted in a location that is exposed to the air in the environment of the room or area being monitored. The motion detector transducer and sensor circuit is preferably mounted in a manner such that it is not exposed to (1) the air flow from the environment being monitored and (2) the air flow which may be created when the device is mounted in or on a hole in the wall. Further, the hole in the wall is often created when the device is mounted on a wall in a home or office building. The hole may function to create a chimney effect given the right conditions. It is thus desirable to mount the temperature sensor in a way which offers some shielding or insulation from direct exposure to heating or air ducts as well as any other undesirable heating or cooling sources such as direct sunlight, fans, HVAC ducts, etc.
The present invention is a multifunction sensor and thermostat device that provides various transducer functions and the ability to control temperature. In particular, the device comprises a means for performing temperature sensing and control, humidity sensing, ambient light sensing, motion detection, switching, relay control, dimming functions and a means to put the device in an on, off or auto mode. The device can optionally employ a cool/off/heat and fan on/auto switch that places the heating and cooling equipment in the appropriate state. Alternatively, it can perform these functions over the network via software control. Additionally, the device can also interface with master or slave thermostats and can turn on and off all types of fans (including ceiling and tabletop fans), heating units and cooling units. The device can also be linked to the on/off xe2x80x98killxe2x80x99 switch commonly used for boilers and hot water heaters. This ensures that the heating unit stays off in the summer months. Such a device has utility in environments such as that found in offices, schools, homes, industrial plants or any other type of automated facility in which sensors are utilized for energy monitoring and control, end user convenience or HVAC control.
Key elements of the present invention include (1) overcoming the difficulty of mounting diverse sensors or transducers within the same device or housing, (2) permitting these various sensors to exist in a single package that can be mounted to a wall in a substantially flush manner, (3) an embodiment that eliminates the requirement of an air flow channel in the device, thus minimizing any adverse effects on the motion detecting element or sensor as well as providing built in partial hysteresis and practical latency, and (4) an embodiment that utilizes an air flow channel in the device for drawing air over a temperature sensor and/or humidity sensor.
A prime objective of the present invention is to provide a flush or surface mounted temperature, humidity and motion detection sensor in a single device. The device may include additional transducers or sensors and, in one alternative embodiment, is constructed such that the temperature and humidity sensors are neither exposed to the flow of air in a room or area nor in an airflow channel whereby a chimney effect may occur. To avoid these conditions from occurring, the temperature and humidity sensing elements are placed in a cavity that is coupled to the environment. Thus, the temperature and humidity of the air in the cavity changes via diffusion with the temperature and humidity in the surrounding environment. In addition, the temperature and humidity sensing elements, e.g., passive or active infrared sensor, is mounted so as to be shielded from exposure to direct sunlight and so as not to be exposed to a flow of air from the environment being monitored.
Further, the vents provided for the temperature and humidity sensing element function as a baffle to provide hysteresis. The hysteresis provides additional utility for the device in that the temperature and humidity sensing elements are mounted within, beneath, part of, or on the housing in such a way that the chimney effects due to airflow in the wall or from heating or cooling ducts nearby are reduced or eliminated in a fashion that is similar to a xe2x80x98smoothingxe2x80x99 or softening affect and can be adjusted mechanically and/or electronically through hardware or software such that the hysteresis can be xe2x80x98settablexe2x80x99 to any achievable value and could even approach zero hysteresis if desired. Note that the temperature and humidity sensor modules can be incorporated in a flush mount device, wall or surface mount device or ceiling device. Further, since an air channel is not required or used the device can be mounted flush in a single or multiple gang electrical box.
Another objective of the present invention is to provide a means of temperature sensing utilizing multiple technologies including RTD, PRTD, thermisters, digital temperature sensors, PWM sensors, silicon sensors, capacitive and polymer sensors, etc. One or more sensors can be used in the circuits that are coupled to a microprocessor or microcontroller. The sensor is positioned in a modular temperature chamber that permits the temperature sensor to acclimate to the ambient air temperature in the surrounding environment. Access to the temperature sensor is simply achieved by removal of a cover or panel without the need for special tools.
Another objective of the present invention is to provide a means of humidity sensing utilizing one or more technologies including the Dunmore Sensor, polymer capacitive type, carbon type, digital humidity sensors, automatic chilled mirror type sensors, silicon sensors, oxide and IR hygrometer sensors, etc. One or more sensors can be used in the circuits that are coupled to a microprocessor or microcontroller. The sensor is positioned in a modular temperature chamber that permits the humidity sensor to acclimate to the ambient air conditions in the surrounding environment. Access to the humidity sensor is simply achieved by removal of a cover or panel without the need for special tools.
The microcontroller is utilized to provide the capability of transmitting and receiving real time data, relative data and actual discrete data in addition to switching and controlling loads locally or remotely. Data can be sent and received from other devices that are part of the distributed or centralized control system wherein devices communicate with each other using standard protocols such as Echelon LonWorks, CEBus, X10, BACNet, CAN, etc. The media utilized may comprise twisted pair, power line carrier, RF, optical fiber, coaxial, etc.
The device also has the capability of self-calibration of the sensors under either local or remote control. For example, if the device is exposed to two different known temperatures, then the equation of a line including the slope and relative offset connecting the two points can be generated. This procedure can be performed once and either actual or relative readings can be calibrated within the operating range of the device. In addition, points can be recorded and used to provide additional accuracy or to extend the range of the temperature sensor. Further, a piece-wise linear, logorithmic or other arithmetic equation and look up table can be generated which is used to linearize the accuracy or sensitivity of the temperature sensing element and associated circuitry and to provide for sensing over a larger temperature or humidity range. In addition, local test resistors or potentiometers can be used to adjust the range, sensitivity or accuracy of the sensor. A similar procedure can be used for calibration of the humidity sensor.
Another key element of one alternative embodiment presented herein, is that the temperature and humidity sensors do not have airflow channel that permits air to circulate through the sensor module housing. Rather, the device has a passive alcove or cavity that acclimates to the ambient air temperature and humidity through the process of diffusion. In addition, the device incorporates a vent that permits any heat generated by electronics or components to escape without adversely affecting the temperature sensor and passive infrared sensor. In addition, this permits any chimney effects generated by the hole in the wall to be measured by the device.
The device incorporates a temperature sensor transducer and sensing circuit that is mounted in the sensor device housing in a location that is exposed to the air in the room but not to air circulating internally within the device housing. A passive or active infrared sensor or ultrasonic sensor is also mounted within the device housing with or without an insulating layer of material or conformal coating located such that it is not adversely affected by the venting of heat generating components or the chimney effects generated by the mounting hole and the vent.
The device also comprises airflow vents on the top of the device housing to provide a venting means for any components that generate heat within the device. These vents also provide airflow from the mounting hole or the channel between the studs commonly found behind a wall within a building or wall. This flow of air provides for additional cooling of heat generating components in the device and ensures that the temperature and motion detection sensors are not adversely effected by this airflow.
Optionally, a sensor could be used to measure this air flow which could subsequently be used for building maintenance purposes, i.e., to notify the building owner of the location of air leaks within the walls of the building. Note that in most buildings, insulation is placed in the wall of a building to reduce the hot or cold air losses thus saving utility expenses. In this case, the device can be used to detect and measure the airflow that occurs in a wall and notify building personnel that a wall in which the device is mounted does not have adequate insulation and/or is not properly sealed. The vents could also be provided on any other surface of the device including opposite side surfaces or the bottom of the housing to provide additional or alternate venting.
In another embodiment, the device provides airflow channels that connect vents on the outer surface of the device to the chamber housing the temperature and humidity sensing elements. Airflow is directed into the wide vents on the outer surface, over the temperature and humidity sensing elements and up the channels to exits from the vent opening on the upper portion of the device.
The device also may include provisions for surface wiring and various types of mounting means. Included as well is an optional positive screw mounting. The mounting means could be directly on a wall, on a modular furniture channel or on or in a single gang wall box. The electrical connections can be made using flying leads, terminal blocks, binding screws, or an RJ-11 or RJ-45 jack.
A lens is positioned in front of the infrared detector to focus infrared radiation and to prevent the ambient air from entering the device either from the temperature and humidity chamber or the heat vent. The lens may or may not include blinders.
Optionally, the front PC board containing the passive infrared transducer and the temperature and humidity sensors is installed using a layer of glue, foam or other gasket material to isolate the temperature and humidity sensor transducers and the infrared sensor from the back boards and the air channel created by the heat vent and the hole in the wall.
Optionally, two infrared sensing elements can be mounted on the same side of the printed circuit board. Partitioning of the two sensors can be performed arbitrarily as long as the passive infrared sensor is not exposed to erroneous air flows created by a natural or artificial air channel from the vents in the housing, the hole in the wall or the vents for the temperature chamber. Further, the motion sensing transducer is preferably not exposed to airflow or any other environmental conditions that could cause adverse behavior to the performance of the device. The temperature and humidity sensors are isolated with the absence of airflow over or around the infrared sensor. The housing is constructed such that it provides a chamber permitting the temperature and humidity to adjust naturally to the ambient air temperature and humidity to which it is exposed by the process of diffusion. This is accomplished by the use of the housing and a cover plate that is positioned over the temperature and humidity sensing elements. Foam or insulating material may optionally be used since the temperature and humidity elements are not in a channel where air is circulating, but rather is in an alcove chamber that acclimates to the environment.
In another optional embodiment, the passive or active infrared and temperature and humidity sensors are on opposite sides of the printed circuit board or on different boards such that the air around the temperature and humidity sensors and the passive or active infrared sensor are isolated from one another by the nature of their location.
The device may incorporate at least one vent on the face of the device to allow the ambient air outside to acclimate with that of the temperature and humidity chamber. Thus, the temperature and humidity sensors may be located centrally behind the vents or louvers or anywhere within the area. In addition, the sensitivity, range, response time and accuracy may be adjusted mechanically, via the use of different housing and vent shapes and materials and also by electronic means. The vents are also constructed to be a protective cage for the sensors. Grooves in the plastic and other means can be used to hold and/or align the sensors as well.
Further, the device may incorporate adjustable louvers or vents over the temperature and humidity sensors to create a baffle or regulator to adjust how quickly or slowly the temperature and humidity transducers will adjust to the ambient air. Also, the sensitivity, range, response time and accuracy can be adjusted by adapting the layout, position and design of the vents or louvers. It is also within the scope of the invention that mechanical or electronic means may be provided that open or close shutters on the vents over the temperature and humidity sensors.
Optionally, the device may incorporate fixed vents over the temperature and humidity sensors that create a fixed baffle or regulator thus determining a fixed means for how quickly or slowly the temperature and humidity transducers will adjust to the ambient air. The sensitivity, range, response time and accuracy, however, can still be adjusted by using different materials, thickness and shapes and by locating the sensor in different locations and orientations.
In another optional embodiment the device does not incorporate any vents and the temperature sensors is attached to the cover. In this case, the outside ambient air will be measured by measuring the inside surface temperature of the cover or plate. Therefore, the temperature sensing transducer is not directly exposed to any outside air. Also, the sensitivity, range, response time and accuracy may be adjusted using different materials, thickness and shapes and by locating the sensors in different locations or orientations.
In yet another optional embodiment of the invention the device does not incorporate vents and the temperature sensor is mounted on the surface of the device or in an alcove and exposed directly to the air. The outside ambient air is measured by measuring the air temperature of the outside air. Therefore, the temperature sensing transducer is directly exposed to the outside air. In addition, the sensitivity, range, response time and accuracy may be adjusted using different materials, thickness and shapes and by locating the sensors in different locations or orientations.
Also, heat sinks can be added or connected to the sensor body and/or the leads and brought out of the device so as to improve the overall temperature response of the transducer and the device.
In still another optional embodiment of the invention the device does not incorporate vents and the temperature sensor comprises a cover on the device or a portion of the cover of the device and exposed directly to the air. The temperature-sensing element can also be either predominately outside, part of a cover or inside a cover of the device. This allows for very thin sensing materials to be used that are placed directly on the surface of the device, embedded in the layers of the cover of the device or predominately located on the inside portion of the cover of the device. The outside ambient air temperature is measured by measuring the air temperature of the outside air. Therefore, the temperature sensing transducer is directly exposed to the outside air.
In addition, the sensitivity, range, response time and accuracy may be adjusted using different materials, thickness and shapes and by locating the sensors in different locations or orientations. Although the temperature sensing element and housing can take on various forms, some of the types are enclosed. A software algorithm can be optionally employed which functions to correct the hysteresis by adjusting the actual temperature reading and hence approximating the theoretical response of a highly calibrated thermocouple. Additionally, the algorithm can employ programmed undershoots, overshoots, delays, amplitude shifts and a variety of other signal manipulations.
Additionally, since the temperature sensor may be exposed to the open air, a xe2x80x98fast change algorithmxe2x80x99 can be employed which functions to recognize a rapid rate of change of temperature at the sensor, e.g., more than 15 degrees per 10 seconds or alternatively, that the slope, i.e., rate of change, of the temperature reading relative to time is greater or less than some absolute value. The rapid temperature change may either be due to someone placing their finger on the sensor, applying a heat gun, applying a cold compress or may be due to flames from a fire. The software routine, in response to the detection of a rapid rate of change in temperature, can either send a warning message over the network or ignore the change in temperature, regarding it as an artificial heat/cold source. The device can be programmed to respond either way, i.e., sending temperature data over the network and having it acted upon or internally filtering it out and ignoring it.
Also, hardware and software can be employed to increase the sensitivity and accuracy of certain temperature and humidity ranges. For example, consider the temperature sensor circuitry having a temperature range of 0 to 50 degrees. Also, assume it is broken into segments that are piecewise linear, logarithmic or represented by some other mathematical relationship. For example, one range spans from 0 to 15 degrees C., another from 15 to 30 degrees C. and the last from 30 to 50 degrees C.
To achieve increased accuracy within a span, for example, the 15 to 30 degree range, a user would select this range over the network and software means would provide greater resolution in that particular range while sacrificing some resolution in the other ranges. This allows for users to choose a certain temperature range to be processed at a higher accuracy and the other ranges to be monitored using less accuracy. This can be implemented via software and/or hardware by utilizing two different circuits, each having different accuracy""s for the thermistor and different gains for the electronics.
In another embodiment the cover over the temperature and humidity sensors is removable. The cover can be adapted to either require or not require a tool for removal. Alternatively, the cover can be fixably attached to the device. In either embodiment, the temperature and humidity sensing transducers and/or other components of the sensing circuits are in a socket which permits replacement with another transducer or component with different parameters. In addition, any local components such as potentiometers, switches, etc. requiring adjustment can be accessed, adjusted or changed.
In one embodiment of the invention the software may be adapted to adjust the sensitivity, response time, accuracy, range, etc. of the temperature and humidity sensor elements and associated circuitries. In another embodiment, at least one air vent is provided which exposes both sides of the back PC board to the potential airflow generated when electrical components generate heat. In addition, the temperature and humidity chamber may be located in different parts of the device such as centrally or at the top or bottom.
The device may be mounted using a variety of means. These include various mounting plate variations including mounting in a single or multiple gang box, mounting on or in the hole of a modular furniture channel, raceway, or being hung from underneath a fluorescent or incandescent fixture that is mounted on the desk, wall, floor or modular furniture and mounting on any other suitable surface. In addition, the device contains xe2x80x98mouse holesxe2x80x99 which allow surface wiring to exit the device.
Another mounting option includes a hinged mounting bracket that permits the device to be mounted and electrically connected relatively easily. The mounting means uses either a positive locking screw or a snap fit. The positive locking screw option makes the device more tamperproof. The snap fit option provides a more aesthetically pleasing package.
Another optional feature is the use of a press to release button to allow for the device to be easily removed from the wall. This allows for the device with its lighting and temperature sensor and controls to be removed from its fixed position on the wall and moved freely about the room. It can be placed in a more desirable location or can be used as a remote control as well as a regular wall mounted or table top switch or dimmer, sensor or thermostat as well as to adjust and control all natural and artificial lighting, temperature and humidity devices.
The multi-sensor device of the present invention forms part of the network control system and generally comprises the following basic elements: (1) user interface and controls, (2) power supply and media connections, (3) communications media and protocol (4) load switching or dimming elements and (5) one or more sensor inputs.
Additionally, functions can be performed which include some type of annunciation either by sound by using a buzzer or by sight by employing LEDs or controlling the lights in the room. For example, if the smoke detector transducer detects a fire, a buzzer could perform local annunciation. Alternatively, it could illuminate a visual indication or act as a xe2x80x98notification appliance,xe2x80x99 e.g., specially designed lights, LEDs, etc. for people that are hearing impaired. Also, a signal can be sent to a control unit or lamp actuator to flash one or more lights in the event that fire is detected for the benefit of the hearing impaired.
The power supply component for some of the devices in the system may include means to operate from 100 to 347 VAC. This type of device supplies a nominal output voltage between 8 and 26 VDC and 8 to 24 VAC. Alternatively, the device may omit a power supply that converts utility power but rather is adapted to receive power from another device that does incorporate a power supply that operates from 100 to 347 VAC. The means for distributing the electrical power to other devices could be accomplished via any suitable means including twisted pair cabling, electrical power line cables or any other power carrying media.
Another key feature of the system is a communications media and protocol that together form a communications network allowing messages to be communicated (1) between devices within the system and (2) between devices located within the system and devices located external to the system. The messages comprise, among other things, commands for controlling and/or monitoring signals. These messages could be tightly coupled, loosely coupled or of a macro broadcast nature. In addition, they may be one way simplex, half or full duplex bidirectional, with established priorities or without. The network communications medium may comprise, for example, twisted pair Category 5 cabling, coaxial cabling, a standard POTS line, power line carrier, optical fiber, RF or infrared. The medium may be common or it may be shared with the possibility of requiring the use of gateways, routing devices or any other appropriate network device for carrying data signals.
Depending on the type of network medium in use in the system, the devices within the system include, within their housings, a slot that allows for the connection of a bus terminator. The bus terminator is typically an RC network that is connected to the device and serves to mechanically as well as electrically connect the device to the network communication line, e.g., twisted pair, coaxial, optical fiber, etc.
Thus, the system is able to communicate to devices within the system to provide intrasystem control and monitoring as well as to communicate outside the system to provide intersystem control and monitoring. Data and/or commands are received and transmitted, real time relative readings can be received and transmitted, devices can be calibrated externally in an automatic self adjusting way or via a communication link over the network.